Quality of life (QOL) is an extremely important concept in the promotion of
appropriate and successful health care programmes. However, there is a need
for conceptual clarity to unravel the complexities of terminology in different
medical conditions and the underlying factors that have a direct influence on
the quality of life for people with coronary heart disease.
The primary objective of this thesis is to propose a theoretical model which
specifies the domains of QOL and the interrelationships among these domains.
The objectives of the study are four-fold: (1) To examine whether a cardiac
rehabilitation programme has a beneficial effect on cardiac heart disease
patients; (2) To evaluate the primary components of generic health-related
quality of life assessment tools for people with coronary heart disease; (3) To
identify the main factors governing disease-specific health-related quality of life
assessment tools amongst patients with coronary heart disease; (4) To examine
a variety of conceptual models of QOL and to determine their relevance to
cardiac patients.
First, in order to provide conceptual clarity, a comprehensive review of QOL
measures was undertaken. Second, data was collected on a cardiac
rehabilitation programme in a county hospital using Short Form-36 (SF-36) and
Quality of Life for Myocardial Infarction (QLMI) instruments. This data was
analysed using a number of techniques including (l)meta-analysis;
(2)discriminant analysis; (3)factor analysis and (4)structural equation modelling.
Analysing the data in this way enabled the development and clarification of the
specific domains of the quality of life model.
Meta-analysis involved pooling the results of several studies, these were then
analysed to provide a systematic, quantitative review of the data. The results
found that the related studies did not have consistent outcomes to support the positive effects of a cardiac exercise rehabilitation programme on quality of life
in coronary patients.
Findings from the SF-36 indicate that older people with coronary heart disease
gain more pain relief than their younger counterparts. After a cardiac exercise
rehabilitation progranune, statistically significant improvements occurred in
physical function, social function, role limitation/physical, energy/vitality,
body pain, and change in health-related dimensions of quality of life. The
first-order five domains model includes the symptom domain, the restriction
domain, the confidence domain, the self-esteem domain and the emotion
domain. This model represents an appropriate model of quality of life for
people with coronary heart disease compared to the three-domain model and
the four-domain model. In terms of the second-order QOL model, the
five-domain model also has an adequate fit to the data.
According to the result of structural equation modelling, three models,
including the null model, the alternative model I and the alternative model n,
did not fit the data perfectly. However, the construct of full latent variable
model gradually increased the fit statistics from the null model to the
alternative model I and from the null model to alternative model n. Therefore,
it can be concluded that the paths and indicators of the three models need to be
further adjusted in order to provide a more appropriate model. Nevertheless,
this is a first trial to examine a full model of quality of life for people with
coronary heart disease using the structural equation analyses. As such, this
study provides a new approach to examining the difference between empirical
studies and theoretical approaches.

Description:

A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.